COMT_HIERARCHY_DATA is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "Hierarchy Data" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately. i.e. DATA: wa_COMT_HIERARCHY_DATA TYPE COMT_HIERARCHY_DATA.
The COMT_HIERARCHY_DATA table consists of various fields, each holding specific information or linking keys about Hierarchy Data data available in SAP. These include ROOT_CAT_GUID (Category GUID), SCHEME_GUID (Numbering Scheme GUID), CAT_AUTONUMBER (Automatic Number Assignment), MULTI_SYS (Hierarchy Contains Categories from Several Systems)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .